What each slider does
Exposure brightens or darkens the whole picture as a camera would, by working on light values rather than screen values, so it is the slider to reach for first when a photo is simply too dark or too bright. Brightness moves the middle tones while leaving the deepest black and the brightest white in place, which lifts a shadowy face without washing out a window. Contrast pushes darks and lights apart for punch, or pulls them together for a softer look. Saturation sets the strength of colour, from black and white at the far left to bold at the far right. Warmth shifts the colour towards orange or blue to correct indoor lighting or to set a mood. Sharpen brings out fine edges such as hair, text and leaves; a little goes a long way. Vignette darkens the corners to draw the eye to the centre, and moving it left lightens them instead for an airy look. Each number can be tapped to reset that slider.
Filters you can tune
A filter is a starting point, not a final answer. Vivid and Golden suit food, travel and sunsets; Cool cleans up beach and snow scenes; Mono, Noir and Sepia turn a photo into black and white or brown tones; Fade and Vintage give the soft, lifted blacks of printed film; Dramatic adds contrast, crisp detail and darker corners. Each tile shows the filter on a small copy of your own picture, so you can see the result before you tap. The strength slider blends the filter with your photo from 0 to 100 per cent, and your own slider settings stay on top of it, so you can, for example, pick Vintage and then make it a little brighter.
Full resolution, no upload, honest limits
The saved file has the exact pixel size of your photo, or of the crop you chose: nothing is scaled down to save work. The preview you see is a smaller copy made by the same code, and the heavy pixel work runs in a background thread, so the sliders stay smooth on large phone photos. Everything happens in your browser, and the photo is not sent anywhere. Phone photos are turned the right way up first, iPhone HEIC photos are decoded on your device, and transparent PNG areas stay transparent when you save as PNG or WebP (JPG has no transparency, so they become white). Because the new file is drawn from pixels, camera data such as GPS location is not copied. Photos up to 50 megapixels open in most desktop browsers; phones may refuse very large images. This editor works on the whole photo; to remove the background, blur faces or shrink the file size, use the tools linked below.
Which format to save in
JPG is the safe choice for photos: every phone, website and printer accepts it, and a quality of 85 to 92 looks the same as the original to most eyes while keeping the file small. PNG is lossless and keeps transparency, so it suits screenshots, logos and graphics, but a camera photo saved as PNG is several times larger. WebP makes smaller files than JPG at similar quality and keeps transparency; most current browsers open it, but some older programs and upload forms still reject it. If a form needs a file under a size limit, save as JPG here and then use the compressor.